18 



APPENDIX. 



2. Notes on a few 'previously described species. 



198. BrooJcite. A. Schrauf announces that his recent crystallographic studies liave proved 

 brookite to be monoclinic and isomorphous with wolframite (Jahrb. Min., 1871, 163). 



636. Caledonite. Schrauf has found this species to be monoclinic in crystallization. He 

 makes «Am=132° 32', and a Ac— 90' 30', a, m, c, being the planes so lettered in Miller's 

 Mineralogy, and corresponding, a to i-%. m to 7, and c to 0, in this work. (Jahrb. Min. , 

 1871, 374.) 



Ephesite, see Lesleyite below. 



24. Diamond. P. v. Jeremejew has discovered minute crystals of diamonds irregularly 

 distributed through plates of xanthophyllite from the Sehischimskian Mountains near Slat- 

 oust. They are readily recognized when magnified 30 diameters, and with 200 diameters 

 their crystalline form is seen to be that of the hexa-tetrahedron 3-| combined with the tetra- 

 hedron, the first four being distinctly convex, while the tetrahedral plane is flat (like fig. 59 

 p. 21, except that there are also small flat tetrahedral planes). Most of the crystals are 

 colorless. They are symmetrically disposed in their matrix, their trigonal intermediate axes 

 being vertical to the foliation of the xanthophyllite. The green plates of this mineral, near- 

 est the rounded masses of the talcose slate and serpentine enclose unusually large numbers 

 of them and they are likewise found in the two rocks themselves. Jahrb. Min., 1871, p. 

 275 in Am. J. Sci. , III. iii. 57. 



Lesleyite. The mineral named lesleyite by I. Lea (see p. 800) has been analyzed by S. P. 

 Sharpies (Am. J. Sci., II. xlvii. 319) and J. L. Smith (ib. xlviii. 254). Sharpies examined 

 two varieties, one white (anal. 1), and the other red (anal. 3). Smith analyzed the white 

 mineral (anal. 2). 



Si £l Pe Ca 



1 white, 33-59 55-41 tr 



2 " 3118 55-00 045 



3 red, 47-00 33-27 2-84 



The analysis of the red variety was made under Sharples's direction by C. W. Roepper. It is 

 an entirely different substance from the white mineral, and was properly referred to pinite 

 by Sharpies. 



Smith compares the composition of the white variety with that of his ephesite (see Min. , 

 p. 507) of which he gives the following new analysis. 



Si Si Ca Na K H 



Ephesite 30"70 55"67 2'55 552 1-10 4-91=100.45 



There is also a very close correspondence in the physical as well as in the chemical charac- 

 ters of the two minerals, and they are evidently closely related. Lesleyite is found associ- 

 ated with diaspore and both minerals have a peculiarity in regard to their hardness that 

 suggests a want of homogeneity. They are easily scratched with a knife, but they both 

 contain particles which scratch topaz. Under the magnifier they both present glistening 

 scales which are soft and apparently micaceous. It is evident that the minerals are mix- 

 tures of corundum and probably diaspore with a mica similar to the damourite found at 

 the lesleyite locality ; and that the foliated soft mineral is damourite or a hydrous mica 

 near that species. 



Pattersonife. This substance, classed temporarily under the mica group in the supplement 

 to this mineralogy (p. 801), has been analyzed by S. P. Sharpies with the following results 

 (Am. J. Sci, II. xlvii. 309). 



Si Pe Si Mg Xa Li K H 



30-20 14-88 2055 1'28 tr 11-35 11-73=89.99 



The potash is stated to have been determined by the difference (loss), but the analysis 

 foots up, exclusive of the potash, only 78-64 leaving 21 -36 for potash instead of 11*35. This 

 large error runs through the calculated oxygen ratios, and hence is not typographical.^ In 

 view of it, the analysis leads to no satisfactory conclusion. The percentages of silica, iron, 

 alumina and water are very near those of prochlorite. 



^a 



K 



H 



tr 



7-43 



4-30=100-73 



1-20 



7-28 



480=99.91 







9-97 



6-71=99.79 



